Make job name check optional in SageMakerTrainingOperator

[olivermeyer]

closes: #16299

In this PR I make it possible to avoid listing existing training jobs by adding a check_if_job_exists parameter to the SageMakerTrainingOperator.

[boring-cyborg]

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[github-actions]

The PR is likely OK to be merged with just subset of tests for default Python and Database versions without running the full matrix of tests, because it does not modify the core of Airflow. If the committers decide that the full tests matrix is needed, they will add the label 'full tests needed'. Then you should rebase to the latest main or amend the last commit of the PR, and push it with --force-with-lease.

[olivermeyer]

@kaxil thanks for reviewing. Is there anything else I need to do to get this merged?

[boring-cyborg]

Awesome work, congrats on your first merged pull request!

[kaxil]

Nope, all good @olivermeyer 👏

[shlomiken]

thanks for this @olivermeyer , is there any plans doing that for processingJob /transformJob as well ?
i considered doing that myself - but i guess the kick start develop in this repo is not so quick is it ?